转soccer88给你的链接里的解决办法，但是有点费事，既然灯亮实际也无需改动

Normally when you flip your turn signal switch, the light blinks at a set, slow pace. However, if you have modified your lights to use LEDs, you'll notice that the turn signals now blink very quickly. This is caused by the low resistance of the LEDs due to the fact that they use less energy. To correct the problem, you'll need to wire the turn signals in a parallel circuit. To do this, you'll be installing a resistor.
这里说的解决办法就是在新灯口处并联焊一个适当的电阻（在这建议，阻值参考该种钨丝灯泡内阻，取比其大几倍，如5倍10倍，可行的话尽量往大选），但是转向灯是双灯丝结构（应该一个灯丝是转向亮，另一个是刹车亮吧），你要分清电阻应并联在转向那个灯丝端子，分不清楚的话就两面各试一次。最懒办法是任嘛甭管，任其快闪吧
Read more : http://www.ehow.com/how_5463302_fix-blink-led-turn-signals.html